Sponge backrest



FIG. 1 is a perspective view of a sponge backrest showing our newdesign;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof;

FIG. 8 is a perspective view viewed from another visual angle thereof;

FIG. 9 is a perspective view of the sponge backrest in a use state; and,

FIG. 10 is a cross sectional view taken along the line 10-10 in FIG. 2.

The broken lines illustrate the claim in use and form no part of theclaimed design.

CLAIM The ornamental design for a “sponge backrest”, as shown anddescribed.